Recently, a telemedicine is a sharply developing application of clinical medicine where medical information is transferred via IP network or the Internet for the purpose of consulting, and sometimes remote medical procedures or examinations. In medical imaging, picture archiving and communication systems (PACS) are computers or networks dedicated to the storage, retrieval, distribution and presentation of images. PACS application over the Internet is one of the poplar telemedicine. Traffic Engineering (TE) approaches are mainly proposed to utilize networking resources. In order to enable TE to work effectively, a criterion of PACS metric is needed to evaluate the quality of end-to-end path over the Internet. This paper presents a novel PACS metric that takes the number of “Qualified Flow: QFlow” as the criteria to evaluate the end-to-end path capability for PACS flows. The proposed metric is based on the regression methodology. The proposed metric helps TE to make a decision for routing or/and forwarding at the end path. For example, a load balancer at the end path can use a path cost calculated by such metric to make a decision to distribute PACS traffic over several available end-to-end paths more efficiently. The experiment results proved that the proposed method give the high accurate estimation.